scholarly journals COMPARATIVE ASSESSMENT OF GASEOUS FUEL EMISSION

Author(s):  
Olena Hryhoriivna Levytska ◽  
Yulia Vladimirovna Voytenko ◽  
Anastasiia Oleksiivna Orishechok

The work presents estimated comparative assessment of emissions release in combustion products during work of high–power steam boilers with the use of traditional fuel – natural gas and alternative fuels – blast–furnace and coke–oven gases generated in the process of technological cycle at iron and steel and coke–chemical enterprises. Calculation algorithm is shown and formulas for assessment of carbon content in exhaust gases are defined, conclusions on ecological efficiency of gaseous fuels are given. The purpose of the work was to evaluate the emissions of harmful substances generated during the combustion of natural, blast furnace and coke oven gases, justification of the calculation of carbon content of a given chemical composition and determine the optimal environmental impact of analogues of natural gas. The comparative estimation of pollutant emissions into atmospheric air during combustion of natural, coke oven and blast furnace gases revealed: – high sulfur dioxide emissions from combustion of blast furnace and coke oven gases due to the presence of sulfur compounds in the composition of these gases; – relatively high emissions of nitrogen compounds for natural and coke oven gases and relatively low emissions for blast furnace gas; – сarbon emissions are high for all types of fuels which have been considered, most carbon dioxide gets into  the air when burning natural gas, least – when burning blast furnace gas; – significantly higher methane emissions are observed during the combustion of natural and coke oven gases, respectively, smaller – for blast–furnace gas combustion; – coke oven and natural gases are characterized by low mercury emissions. Comparative assessment of the calculated values of hazardous substances emissions in the combustion products in the process of combustion of natural, coke–oven and blast–furnace gases shows that even at lower working heat of combustion values the coke–oven and blast–furnace gases can compete with natural gas. For the first time, a comparative characterization of the emissions of harmful substances in the combustion of natural, coke oven and blast furnace gases is presented, and it is shown that the gases used in coke and metallurgical industries, which are used as analogues of natural, are logical to use, but require the installation of treatment systems. The paper defines a formula for calculating the carbon content in natural gas from the Urengoy–Uzhhorod gas pipeline. The provided calculations and the introduction of simplified formulas serve as an example for the calculation of emission factors and emissions in assessing the level of safety of existing equipment and can be used in the development of permit documents of enterprises that carry out emissions of harmful substances to the environment.

Author(s):  
Edoardo Bertolotto ◽  
Alberto Amato ◽  
Li Guoqiang

Abstract The present paper describes atmospheric experimental tests of a new Ansaldo Energia full scale burner which was designed to burn fuels byproduct of steel making processes (mixtures of Blast-Furnace Gas (BFG) and Coke-Oven Gas (COG)), characterized by very low heating values (LHV∼2–3.5 MJ/kg) and very low stoichiometric air/fuel ratios (∼0.5–1 kg/kg). In particular, flame stability and blow-out margins were assessed for different burner variants and fuel compositions such as pure BFG, blends of BFG with increasing content of COG, and also a synthetic mixture of natural gas, hydrogen and nitrogen (NG/H2/N2). Except for pressure, all burner inlet conditions were simulated as in the actual gas turbine engine. The best performing burner among those tested demonstrated an excellent burning stability behavior over a wide operating range and stably burned pure BFG without any supplementary fuel. Furthermore, considering that in most operating concepts gas turbine engines for Ultra-Low BTU applications require a back-up fuel (such as oil, propane or natural gas) to ignite and ramp up or to perform load-rejections, the present atmospheric tests also assessed maneuvers to switch from natural gas operation to syngas operation. Also in this type of dual-fuel operation the burner demonstrated a wide flame stability range.


Author(s):  
Federico Bonzani ◽  
Giacomo Pollarolo ◽  
Franco Rocca

ANSALDO ENERGIA S.p.A. has been commissioned by ELETTRA GLT S.p.A, a company located in Trieste, Italy for the realisation of a combined cycle plant where all the main components (gas turbine, steam turbine, generator and heat recovery steam generator) are provided by ANSALDO ENERGIA. The total power output of the plant is 180 MW. The gas turbine is a V94.2 K model gas turbine dual fuel (natural gas and steelworks process gas), where the fuel used as main fuel is composed by a mixture of natural gas, blast furnace gas and coke oven gas in variable proportions according to the different working conditions of the steel work plant. The main features adopted to burn such a kind of variability of fuels are reported below: • fuel as by product of steel making factory gas (coke oven gas “COG”, blast furnace gas “BFG”) with natural gas integration; • modified compressor from standard V94.2, since no air extraction is foreseen; • dual fuel burner realised based on Siemens design. This paper describes the operating experience achieved on the gas turbine, focusing on the main critical aspect to be overcome and on to the test results during the commissioning and the early operating phase. The successful performances carried out have been showing a high flexibility in burning with stable combustion a very different fuel compositions with low emissions measured all operating conditions.


Author(s):  
B. S. Soroka ◽  
N. V. Vorobyov

The influence of hydration of the components of combustion (air-oxidizer and – in some cases – fuel) including hydration in the conditions of substitution of natural gas by alternative gas fuels, viz. by coke blast furnace mixture and natural blast furnace mixture – on energy efficiency of the use of different fuels has been determined. Calculations of fuel saving for substitution of natural gas (NG) by wet process gas (blast furnace gas (BFG), coke gas (CG), their mixtures) were performed taking into account real technological parameters (on the example of a specific metallurgical plant). All the calculations were performed within the framework of the author’s methodology on fuel substitution grounded on the 1st and the 2nd laws of thermodynamics. The analysis of possibility for saving or overspending NG is performed in the conditions of preservation of the flow of the used total enthalpy (as the main requirement of the methodology that had been proposed) and of taking into account the corresponding efficiency of fuel use. The calculation of the required heat flow of natural gas combustion depending on the content of wet blast furnace gas in NG + BFG mixtures for the cases of NG substitution by process gases has been carried out. It is established that the presence of moisture in the fuel-oxidation mixture always reduces the efficiency of the combustion chamber or the energy process and the unit. In order to increase the efficiency of a high-temperature furnace (boiler), it is necessary to provide heating of combustion components when utilizing the heat of the outgoing combustion products. It is shown that the efficiency of the fuel-using system can be significantly increased when the potential (excess total enthalpy) of the working fluid (combustion products) is activated. There are additiоnal benefits due to the fact that the existing heat of products of combustion with humid air in a full range of temperatures – from the theoretical combustion temperature to ambient temperature under conditions of equilibrium, including account of the heat of condensation – increases with increasing moisture content of the initial components of combustion, viz. air-oxidizer and/or fuel gas.


Author(s):  
S. P. Rogozhnikov ◽  
I. S. Rogozhnikov

The expenses for the blast furnace coke are one of most significant part of the hot metal cost. To save the coke, various technologies are used, capable to replace the coke by cheaper additional fuel (AF), in particular by natural gas (NG). The injection of considerable volumes of NG results in an increase of hydrogen share in the blast furnace gases and in a significant variation in the blast furnace technology. Study of peculiarities of such variations is necessary to use the NG more effectively. Based on the mathematical model of the blast furnace process, estimation of the effect of natural gas hydrogen on changes in the heat and reducing processes along the blast furnace radius was accomplished. A formula was elaborated, confirmed by practice, for calculating the degree of hydrogen usage ηН2 along the radius of the furnace. It was determined, that the reducing action of hydrogen along the furnace radius takes place unevenly –decreasing from the periphery to the axial zone of the blast furnace. To estimate the quantitative relations of the reducing action of hydrogen, parameters of the PAO “MMK” and PAO “ArcelorMittal Krivoy Rog” blast furnaces for a long period of operation were analyzed. It was determined, that in the axial and intermediate zones of a blast furnace, values of criterion RН2, designating the oxygen share in the burden removed by hydrogen, are in the range of 0.11–0.16 and weakly depend on the NG consumption. In the peripheral zone near the walls, the value of R Н 2 sharply increases to 0.22–0.27. In this zone of the blast furnace the quantity the burden oxygen, removed by hydrogen, accounts for 80–85%. Therefore, hydrogen accomplished the heat and reducing processes mainly in the peripheral zone of the furnace. At the NG consumption increase, the ore load should be increased for the peripheral zone, near the walls individually accounting hydrogen action along the furnace radius. This will make possible to increase the degree of hydrogen usage and decrease the coke consumption.


2014 ◽  
Vol 59 (1) ◽  
pp. 105-116 ◽  
Author(s):  
A. Ziebik ◽  
M. Warzyc ◽  
P. Gładysz

Abstract CHP plants in ironworks are traditionally fired with low-calorific technological fuel gases and hard coal. Among metallurgical fuel gases blast-furnace gas (BFG) dominates. Minor shares of gaseous fuels are converter gas (LDG) and surpluses of coke-oven gas (COG). Metallurgical CHP plant repowering consists in adding a gas turbine to the existing traditional steam CHP plant. It has been assumed that the existing steam turbine and parts of double-fuel steam boilers can be used in modernized CHP plants. Such a system can be applied parallelly with the existing steam cycle, increasing the efficiency of utilizing the metallurgical fuel gases. The paper presents a method and the final results of analyzing the repowering of an existing metallurgical CHP plant fired with low-calorific technological fuel gases mixed with hard coal. The introduction of a gas turbine cycle results in a better effectiveness of the utilization of metallurgical fuel gases. Due to the probabilistic character of the input data (e.g. the duration curve of availability of the chemical energy of blast-furnace gas for CHP plant, the duration curve of ambient temperature) the Monte Carlo method has been applied in order to choose the optimal structure of the gas-and-steam combined cycle CHP unit, using the Gate Cycle software. In order to simplify the optimizing calculation, the described analysis has also been performed basing on the average value of availability of the chemical energy of blast-furnace gas. The fundamental values of optimization differ only slightly from the results of the probabilistic model. The results obtained by means of probabilistic and average input data have been compared using new information and a model applying average input data. The new software Thermoflex has been used. The comparison confirmed that in the choice of the power rating of the gas turbine based on both computer programs the results are similar.


2020 ◽  
Vol 20 ◽  
pp. 90-95
Author(s):  
O. Levytska ◽  
O. Sichevii

Feature of the topic and problem statement. The paper presents for the first time a comparative characteristic of emissions of harmful substances from the combustion of traditional fuels (natural gas) and biomass in fuel furnaces of boilers and recommended for the use the most environmentally efficient fuels. Comparative characteristics of emissions of harmful substances during the combustion of various types of fuel allows to determine the optimal type of fuel in the construction and commission of a new power plants, and also adds up-to-date information that will be useful in the scientific and scientific-popular discussions that are widespread today regarding the exhaustion and replacement of non-renewable energy sources, the safety of alternative fuels and their advantages in comparison with non-renewable ones. The purpose of the work is determining of the amount of emissions of harmful substsnces entering the environment during the combustion of natural gas and solid alternative fuels - wood waste, straw, flax straw and sunflower husk, their comparison, justification of calculation of the carbon content in the fuel of a given chemical composition. Findings. During the comparative analysis, high values for the carbon dioxide emissions for all the materials were considered. It is also noted that there are no emissions of suspended solid particles and sulfur diоxide during the combustion of natural gas and it is determined that at its combustion, methane emissions will be the smallest. In as-sessing the level of safety when using unrenewable and alternative fuels, the higher content of methane, dinitrogen oxide and unmethane volatile organic compounds and the lower content of nitrogen oxide, carbon dioxide in emissions from combustion of alternative fuels compared to emissions at combustion of unrenewable fuels were determined during the calculations. When burning natural gas there is mercury in small amounts in the emissions. Originality. The paper presents for the first time a comparative characteristic of emissions of harmful substances from the combustion of traditional fuels (natural gas and fuel oil) and biomass in fuel furnaces of boilers and recommended for the use the most environmentally efficient fuels. When making calculation works the following regularities are defined. In unrenewable and alternative fuels, a higher proportion of carbon passes into carbon dioxide emission and less to carbon oxide emission, while proportion of carbon in carbon dioxide emission is higher in unrenewable fuels. In addition, in unre-newable and alternative fuels, a large proportion of nitrogen is converted into nitrogen oxide emission, and less in emission of dinitrogen oxide, while the proportion of nitrogen in the emission of nitrogen oxide is also higher in unrenewable fuels. The paper defines a formula for calculating the carbon content in natural gas from the Central Asia-Center gas pipeline. The provided calculations and the introduction of simplified formulas serve as an example for the calculation of emis-sion factors and emissions in assessing the level of safety of existing equipment and can be used in the development of permit documents of enterprises that carry out emissions of harmful substances to the environment.


2013 ◽  
Vol 634-638 ◽  
pp. 842-845 ◽  
Author(s):  
Wei Guo ◽  
Jian Jun Wang ◽  
Wen Gui Gao ◽  
Hua Wang

This paper elaborated the technological route of preparing higher alcohols using blast furnace gas (BFG) and coke oven gas (COG) as raw materials. An example was set up a model of environmental and economic evaluation on reutilization of gas as resource.This paper evaluates and analyses as well the efficiency of emission reduction and its economy in terms of reutilization of BFG. The result shows that preparation of higher alcohols using BFG can not only achieve good carbon emission reduction effect, but also get a good economic value.


Sign in / Sign up

Export Citation Format

Share Document